Ostomy bags for receiving bodily waste from colostomy and ileostomy patients are well known. One of the problems faced by users of ostomy bags, particularly colostomy bags, is how to dispose of the contents of the bag.
Many known forms of ostomy bag are made from materials that are not biodegradable and are not easily flushed down a W.C. (that is, a toilet) because of, for example, the buoyancy and relative bulk of the bags. With non-flushable bags, it has been common practice to cut an edge of the bag and then deposit the contents of the bag in the W.C. for flushing away, leaving the soiled bag for separate disposal, e.g. by incineration or by wrapping and placing in a waste bin.
One solution to this problem has been to provide ostomy bags made from materials that are capable of being flushed down a W.C. and examples of such bags are disclosed in WO 94/12128; EP 0259184; US 2004/0059306; EP 0320895; U.S. Pat. No. 5,989,235; GB 2083762; EP 388924; GB 2227668; GB 2193925; and WO 2007/085803.
In many cases, the flushable ostomy bag comprises an inner bag which is formed from a material that disintegrates or dissolves in water or is otherwise disposable and a protective outer bag formed from a material that is resistant to water. The outer bag can be constructed so as to be reusable several times, means being provided for opening the outer bag to permit removal and replacement of the inner bag or liner. The outer and inner bags may both be attached, directly or indirectly, to an adhesive flange which comprises a layer of a bio-compatible adhesive such as a hydrocolloid adhesive to secure the ostomy bag to the body of the patient about the stomal opening.
US 2004/0059306 in particular describes several forms of construction of two piece ostomy bags in which the inner bag or liner is replaceable and a re-fastenable opening is provided in the outer bag to give access to the inner bag so that it can be replaced.
U.S. Pat. No. 5,785,695 (Alcare) discloses ostomy appliances comprising inner and outer bags that are releasably attached to an adhesive flange by means of mechanical couplings comprising coupling rings having annular grooves that engage corresponding annular rims on the adhesive flange to form snap-fit connections.
US 2003/0153883 (Hansen) discloses ostomy appliances comprising an adhesive flange to which is secured a first mechanical coupling ring for the attachment of an outer bag. An inner bag or liner can also be secured to the first mechanical coupling ring by means of a second mechanical coupling ring which encircles the mouth of the inner bag and which forms a snap-fit connection against the radially inner surface of the first mechanical coupling ring.
A problem with ostomy appliances employing coupling rings to connect the inner and outer bags to an adhesive flange is that the coupling rings almost invariably make the appliance stiffer and less flexible and hence less comfortable to wear. In addition, where the coupling rings for the inner and outer bags are placed relatively close together, this can make separation and replacement of the bags difficult, particularly for people with impaired or reduced manual dexterity. A further problem with using coupling rings is that they will need to be removed prior to disposal of an inner bag down a WC. Not only does this add an additional potentially awkward step to the removal and disposal process but it may also result in the user's hands coming into contact with fecal waste at the mouth of the bag.
As an alternative to using mechanical couplings, adhesive bonding has been used to secure the inner and outer bags to the adhesive flange. Examples of ostomy bags making use of adhesive bonding can be found in U.S. Pat. No. 5,865,819 (Hollister) and WO 2004/082452 (Coloplast). U.S. Pat. No. 5,865,819 discloses an arrangement in which the inner and outer bags each have their own separate adhesive flange for direct connection to the body of the patient.
WO 2004/082452 discloses ostomy bags comprising an adhesive flange for attachment to the body of a patient, and inner and outer bags. The inner and outer bags are each provided with adhesive rings for attachment to the adhesive flange. In the preferred ostomy bag constructions disclosed in WO 2004/082452, the outer diameter of the adhesive ring of the inner bag is larger than the inner diameter of the adhesive ring of the outer bag and hence there is overlap between the two adhesive rings.
WO 2007/085803 discloses an ostomy bag assembly comprising inner and outer bags secured to an adhesive flange.